1 From the Department of Neurology (D.O.C.), Vanderbilt University School of Medicine, Nashville, TN; and Department of Neurological Sciences (D.T.-R.), University of Nebraska Medical Center, Omaha. daniel.claassen@vanderbilt.edu.
2 From the Department of Neurology (D.O.C.), Vanderbilt University School of Medicine, Nashville, TN; and Department of Neurological Sciences (D.T.-R.), University of Nebraska Medical Center, Omaha.